dbobjectnav.c

来自「bonddb 是一个源于PostgreSQL封装包的对象。它是一个由C/C++编」· C语言 代码 · 共 181 行

#include <stdlib.h>
#include <glib.h>

#include "dbheader.h"

#include "db.h"
#include "debug.h"
#include "dbobject.h"
#include "dbobjectnav.h"
#include "dbmapme.h"
#include "dbuniqueid.h"
#include "dbtoliet.h"
#include "dbcache.h"

/* Record Navigation Component */

/**
 * db_numrecord:
 * @obj: database object
 *
 * Get the number of rows in a record set.
 *
 * Returns: non-zero on error else number of rows.
 */
gint
db_numrecord(Object * obj)
   {
   if (obj->filtered == TRUE)
      return db_filter_num(obj);
   return obj->num;
   }

/**
 * db_moveto:
 * @obj: database object
 * @row: new row to move to.
 *
 * Move to a new row position in the database object recordset.  This will set the obj->row as
 * well as update everything else in the object to point to the new row.  You can move to records
 * yet to be written as well as back to prevously added records.  IF the @obj has been
 * filtered previously this function will look up the correct corresponding row for
 * its filtered position and move to that row.
 *
 * Returns: non-zero on failure.
 */
gint
db_moveto(Object * obj, gint row)
   {

     if (obj->filtered == TRUE)
       row = db_filter_moveto(obj, row);

   /* check if everything is ok for moving */
   if (row >= obj->num)
      {
      warningmsg("Trying to request a record outside the recordpos");
      return -1;
      }
   if (row < 0)
      {
      warningmsg("Object: %s, pos is less than 0, like %d, oops", obj->name, row);
      return -1;
      }
   /* set the position */
   obj->row = row;
   /* update the cache and id stuff. this is like important. But its sshjit slow. I'll think of something later to do
      aobut this in regard to speeed. It does do the all important obj->id setting */
	/* I finally did something about it being slow. YESS ITS NOT FAST ANYMORE!. disregard comments about it been slow */
	db_cache_moveto(obj);
   obj->mapoutofsync = TRUE;
	  
	   
   return 0;
   }

gint
db_movelast(Object * obj)
   {
   g_assert(obj);
   if (obj->num > 0)
      return db_moveto(obj, obj->num - 1);
   return -1;
   }

/* one word, shit! */
gint
db_movenext(Object * obj)
   {
   if (obj->row + 1 <= obj->num - 1)
      return db_moveto(obj, obj->row + 1);
   else
      return -2;
   }

/**
 * db_copyobject:
 * @obj: database object
 * @row: row to copy
 *
 * A function to copy objects.  If row is -1 then copy all objects,
 * else just copy the requested row.
 *
 * Returns: newly created database object or NULL on error.
 */
Object *
db_copyobject(Object * obj, gint row)
   {
   Object *retobj = NULL;

   g_assert(obj);
   /* return all objects, a direct copy */
   if (row == -1)
      {
      /* Need to flush objects cause of stale objects problem */
      db_toliet_flushall();
      /* run the same query on a new object */
      retobj = db_sql(NULL, obj->query);
      /* move to the record that it is suppose to */
      db_moveto(retobj, obj->row);
      /* update all the other mapped objects */
      db_copymapobject(retobj, obj);
      }
   /* makea copy of just one record */
   else
      {
      if (row >= obj->num)
         {
         db_freeobject(retobj);
			errormsg("Invalid Row Selected");
			g_assert(NULL);
         return NULL;
         }

      /* Need to flush objects cause of stale objects problem */
      db_toliet_flushall();
#ifdef __PORTED
      /* Add in where clause into SQL statement. Man, this is where sql parser is used. yes. */
#endif
      /* run the query */
      retobj = db_sql(NULL, obj->query);
      /* grab the associate objects */
      errormsg("db_copymapobject's hasn't been finished yet, please code this");
      db_copymapobject(retobj, obj);
      }
   return retobj;
   }

gint
db_moverecordbyoid(Object * obj, DbUniqueId * id)
   {
   return db_moveto(obj,db_id_moveto(obj, id));
   }

/**
 * db_currentrow:
 * 
 * Get what row in a table your currently on
 * 
 * Returns: row index
 */
gint
db_currentrow(Object * obj)
   {
   return obj->row;
   }

/**
 * db_moveforce:
 *
 * Like db_moveto() but a forced version of it. You shouldn't normally have to use
 * this function. It forces the dataobject to move to a specific row ignoring
 * all filters that maybe inplace as well as ignoring any tests to see if its
 * physically possible to move here. This will normally have undiseriable results
 */
gint
db_moveforce(Object * obj, gint row)
   {
   obj->row = row;
   return 0;
   }